1. Technical Field
The present invention relates to a surface modified silica by an alkyl sulfonated tetrazole compound, a preparation method thereof, and a resin composition containing the same.
2. Description of the Related Art
Typically, in electronic products such as printed circuit boards, methods of enhancing adhesion or adherence between a resin and a metal include roughening the surface of a resin using desmearing to enhance adherence, or adding an additive to a resin to enhance its adhesive strength (or adhesion). As used herein, the terms “adhesive strength,” “adherence,” or “adhesion” are used as having the same meaning and represent the bondability with a metal.
In the case of roughening the surface of the resin, as the line width of wiring decreases, low roughness is required and thus the effect of the roughness on enhancing adhesion or adherence becomes weak. Hence, the function of an additive for enhancing adhesion, which is added to the resin, is regarded as important. Examples of the additive for enhancing adhesion to a metal include triazoles or tetrazoles, as disclosed in Patent Document 1.
The additive for enhancing adhesion should be uniformly distributed in the resin to maximize enhancement in adhesion of the resin. In order to uniformly distribute the additive in the resin, such an additive may be added in the form of being dissolved in a solvent, or in the form of powder, and may then be distributed. However, this method is problematic because of compatibility between the solvent and the resin and dispersion stability of the powder. Furthermore, Patent Document 2 discloses an epoxy resin having improved curing properties by adding an azole compound such as triazole or tetrazole to the epoxy resin, but does not suggest an improvement in adhesion.    Patent Document 1: EP 0,665,468    Patent Document 2: U.S. Pat. No. 4,322,459